RFID technology has become prevalent in today's society as a means of identifying objects in transit. The objects can be anything from vehicles passing through a toll plaza on a highway and lost pets to merchandise leaving a store and parts traveling along on a manufacturing line. In each of the previously described examples, the mechanism is similar, an RFID tag, activated by an RFID reader, transmits its identity information to the RFID reader for further processing.
Typically, a vendor provides an RFID reader module to parties interested in developing an RFID system by incorporating the RFID reader module in a host device. The host device is responsible for powering the RFID reader module and providing an adequate heat sink to dissipate any heat buildup from the operation of the RFID reader module. In some cases, the host design is not sufficient to provide the heat sink necessary to prevent the reader module from overheating.
In today's RFID reader technology, the circuits powering the RFID reader module are power inefficient and lead to the buildup of heat in the RFID reader module. The RFID reader module provides overheating protection for itself by including a temperature-measuring component and control logic sufficient to shut down the RFID reader module if the RFID reader module approaches a temperature that would damage the RFID reader module. Although this system satisfies the need of protecting the RFID reader module, it is unacceptable to the host device for the reader module to become inoperative at just the time when the host is reading the greatest amount of RFID data.
In another shortcoming of the existing RFID systems, different host devices have different designs and requirements so it is unacceptable to design the reader module to include the heat dissipation capabilities necessary to prevent the RFID reader module from overheating in all circumstances. Market pressure is building to provide an RFID reader module that is more intelligent in its ability to regulate its operation and prevent itself from entering a thermal shutdown if the host device is not capable of dissipating heat at a rate sufficient to allow continued operation.
Accordingly, inefficiencies in existing RFID reader modules, variations in host device implementations and expectations for uninterrupted operation have created market demand for an RFID reader module that can automatically determine whether it is overheating and take steps to moderate its operation so it can continue to function without entering a thermal shutdown.